Download Movement and the Changing Senses Chapter 8

Chapter 8
Copyright © 2016
by Holcomb Hathaway Publishers

Vision:
Most movement tasks are initiated as a result of
receiving visual information
 Helps us to adjust our body in reaction to moving
objects and to emulate movements of others
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Other senses:

Also influence motor development/performance
Copyright © 2016
by Holcomb Hathaway Publishers
If you found yourself walking somewhere at
night, where there were very few street
lights, what senses would you rely on the
most to get you to your destination?
 Would enjoy the walk? Why or why not?

Copyright © 2016
by Holcomb Hathaway Publishers
Copyright © 2016
by Holcomb Hathaway Publishers
Outgrowth of the forebrain
 An inseparable component of the central
nervous system
 Achieves most but not all of its growth before
birth
 Slowest structures to develop:


Muscles that control eye movement and dilator
muscles of the pupil
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by Holcomb Hathaway Publishers

Postnatal changes in visual attributes:
Visual acuity
 Binocular vision and depth perception
 Field of vision
 Eye dominance
 Tracking and object interception

Copyright © 2016
by Holcomb Hathaway Publishers

The ability to see detail in an object
Static visual acuity—target and
performer are stationary
 Dynamic visual acuity—ability to see
detail in moving objects

May play a key role in motor task
performance
 Snellen eye chart

Copyright © 2016 by Holcomb Hathaway Publishers
Age-related macular degeneration
 Glaucoma
 Cataracts
 Diabetic retinopathy
 Presbyopia

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by Holcomb Hathaway Publishers
Healthy vision compared to
glaucoma, age-related macular
degeneration, cataract, and
diabetic retinopathy.
Copyright © 2016
by Holcomb Hathaway Publishers

Eye movements are not coordinated at birth

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Strabismus
Coordinated eye movements are the basis of binocular
vision
Brain uses disparity of information gained from two
different images (binocular vision) as a cue for judging
depth

Conflicting viewpoints on the role of depth perception in
skilled motor performance.
Copyright © 2016
by Holcomb Hathaway Publishers
How much an individual can see while looking
straight ahead and not changing the fixation
of one’s eye
 Peripheral vision (lateral and vertical)
 More limited for infants than for adults

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by Holcomb Hathaway Publishers
One eye tends to lead the other in tracking and
visual fixation
 Unilateral dominance vs. crossed-lateral
dominance:

An athlete with crossed-lateral dominance may have
advantages in tasks such as batting
 Different sports have differing visual demands

Copyright © 2016
by Holcomb Hathaway Publishers
Watching in order to catch an object
 Ocular–motor system
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Smooth ocular–motor pursuit system
 Saccadic eye-movement system
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Coincidence-anticipation
Improves with age
 Greatly influenced by practice

Copyright © 2016
by Holcomb Hathaway Publishers

How well can a person make a motor
response to coincide with the arrival of an
external object? Depends on:
Object speed
 Object predictability
 Viewing time
 Gender
 Age

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by Holcomb Hathaway Publishers
The effects of blindness on the motor
development/performance of children can be
significant
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Head and trunk control
Independent sitting
Creeping
Independent walking
Prehension
Play behavior
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by Holcomb Hathaway Publishers
Less information is available on other senses that
influence motor development/performance
Proprioceptive system
 Auditory system
 Cutaneous system

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by Holcomb Hathaway Publishers
Allows us to be aware of our movements
 Perceive location of body parts without
looking at them
 Body awareness, spatial awareness, and
directional awareness
 Sensory receptors:

Muscle spindles
 Golgi tendon organs
 Vestibular apparatus

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by Holcomb Hathaway Publishers
Auditory stimuli are received, selected,
organized, and interpreted
 Allows us to hear someone (e.g., another
runner in a race) coming up behind us or to
hear traffic when walking or running

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by Holcomb Hathaway Publishers
The skin
 Tactile sensitivity
 Touch, pressure, coldness,
warmth, and pain
 Important role in motor
development/control:

Helps in exploring one’s world
 Romberg’s sign disease

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by Holcomb Hathaway Publishers
What are your thoughts when you learn that
Beethoven composed his greatest works
when he was almost completely deaf, or that
a television dancing competition has at least
one hearing-impaired contestant?
 Does this seem believable to you? Or next to
impossible?

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by Holcomb Hathaway Publishers

Toddlers react to an apparent visual cliff.
Copyright © 2016
by Holcomb Hathaway Publishers